You want your compiler, and execution environment, to support it. In C's case, the compiler can do a lot of work in this department - but so can most modern OS

You want your compiler, and execution environment, to support it. In C's case, the compiler can do a lot of work in this department - but so can most modern OS's in the real-world, provide adequate protection: sbuf = mmap(..,..,MAP_PRIVATE|MAP_ANON); // &etc.